Overhead internal combustion engines, as used in automobiles, motorcycles, trucks, boats and aircraft, are well known in the art. The valves for such engines are retained in the engine block in association with inlet and outlet ports. Each valve has an elongated stem which extends slidably through a perforation in the engine block and is provided with a strong compression spring surrounding the stem externally of the engine block. One end of the compression spring abuts the engine block, while the other end abuts a spring retainer mounted near the free end of the valve stem. The spring retainer is maintained in place by a segmental keeper and the action of the compression spring.
Heretofore, mounting and demounting of the valve assemblies has been a difficult and time consuming operation requiring the use of a special C-clamp to hold the compression spring in compressed condition for removal and mounting of the segmental keeper.
U.S. Pat. No. 3,315,339 teaches a combination tool comprising a valve demounting tool part and a valve mounting tool part. Through the use of these tool parts, properly located in association with a valve assembly, the valve assembly can be mounted and demounted easily and quickly through the administration of an axial blow to the appropriate tool part. No spring-compressing C-clamp or other cumbersome tool is required. The valve assembly mounting and demounting operations can be accomplished with a minimum of manual effort.
The valve assemblies are provided with oil sealing means which must be intact and in good operating order or the internal combustion engine will "use oil". In some valve assemblies, the oil sealing means is located in conjunction with the engine block and the valve stem. In other valve assemblies, the oil sealing means is located in conjunction with the valve stem and the spring retainer. In the use of the combination tool of U.S. Pat. No. 3,315,339, in association with valve assemblies of the type having an oil sealing means in conjunction with the valve stem and the spring retainer, the segmental keeper can be driven too far along the valve stem, to the point where it contacts and damages or destroys the oil sealing means.
The valve assembly mounting tool of the present invention is so designed as to preclude over-driving of the segmental keeper and consequent damage to or destruction of the oil sealing means. The valve assembly mounting tool of the present invention may constitute a separate tool, or it may be configured as an accessory part of the combination tool of the above noted U.S. Pat. No. 3,315,339. For purposes of an exemplary showing, the tool of the present invention will be described in its application as an accessory part of the tool of U.S. Pat. No. 3,315,339. This is done as a matter of convenience, and is not intended to constitute a limitation of the invention.